evans



2 Sheets-Sheet 1. D. EVANS.

STEAM ENGINE.

I (No Model.)

No. 442,313 Patented Dec. 9, 1890.

2 Sheets-Sheet 2. D. EVANS.

STEAM ENGINE.

(No Model.)

No. 442,313. Patented Dec. 9, 1890.

UNITED STATES:

PATENT OFFICE.

' DAVID EVANS, OF CONNELLSVILLE, PENNSYLVANIA, ASSIGNOR TOTIIE BOYTS, PORTER & COMPANY, OF SAME PLACE.

STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent No. &42,813, dated December 9, 1890. Application filed August 4, 1890. Serial No. 360,859. (No model.) i

To aZZ whom it may concern:

Be it known that 1, DAVID EVANS, a citizen of the United States, residing at Oonnellsville, 1n the county of Fayette and State of Pennsylvania, have invented new and useful Improvements in Steam-Engines, of which the following is a specification.

My invention is directed to improvements in steam-engines which are more particularly adapted for operating pumps, and especially mining-pumps, wherein it is of great importance to provide for continuing the working of the pump under a slow movement of the valves, and to avoid in such slow movement the stopping of the pump from variations in the pressure of the steam and from other causes.

In the accompanying drawings I have illus trated my invention in connection with what is known as a steam-pump, but my improvements in the steam-engine, it will be understood, are not limited in such use; but in the combinations illustrated in the drawings the specific improvements in the steamengine give important advantages in a steam mining-pump, because of the necessity for convenient and special provision for continuing its operation slowly when desired and of removing and renewing the pump-piston by reason of its quick destruction under the action of the acids in the water of coal-mines, so that the pump is thereby rendered more durable and can be refitted with new parts without removing the enormously heavy pump from the mine.

Referring to these drawings, Figure 1 is a side elevation of a steam pumping-engine embodying my improvements. Fig. is a vertical cross-section of the same, on an e11- larged scale, taken centrally through the oscillating valve and illustrating the relation thereto of the throttle-valve for preventing the stopping of the pump when it is running very slowly to keep it working. Fig. 3 is a side elevation of the steam-cylinder with the oscillating valve removed. Fig. 4 is a face view of the oscillating valve. Fig. 5 is a side view of the oscillating valve, the bonnet of its valve-chest, and its tappet-arm in separated Fig. 6 IS a side view of the valve relation.

for cushioning the piston and preventing the steam from being cut off entirely when the valve is closed. Fig. 7 shows enlarged views piston-heads.

Referring to Fig. 1, A is the steam-cylinder, and Bis the water-cylinder, the pistons whereof are connected by a bisected pistonrod N N, which is connected with and operates the oscillating valve F of the steam-cylinder by the cross-head K in a way to permit the removal and renewal of the piston-rod and piston of the water-cylinder without disturbing the cross-head connections with the steam-cylinder audits oscillating valve, as I shall presently state. lhe steam cylinder has the usual steam inlet and outlet ports a a, (shown by dotted lines in Fig. 1,) and upon the valve-seat of the cylinder is bolted the steam-chest O, which contains the slide-valve D, which is connected by a neck or flu b with a double-headed piston E, which is operated by steam admitted through the ports (Z (1, leading into the opposite ends of the steamchest, as seen by dotted lines in Figs. 1 and 3, so as to act upon each end of said doubleheaded piston. The oscillating valve F operates to control the admission the steam to and from the ports (Z (Z, and it is of the disk kind having a steam inlet and exhaust opening in its face, as seen in Fig. 4:. It is adapted to fit closely against the face and back of the steam-chest G, and is provided with a stem f, which passes through a stuffing-box g on the bonnet of said chest, and has on its outer end a depending tappet-arm H for operating the oscillating valve from the tappet-rod I, connected with the engi lie-piston, as seen in Fig.1. .This tappetarm 11 is operated by comi n in contact alternately with tappets 767i, secured to the rod I, which is connected to the upper end of the cross-head K, which is connected to the bisected piston-rods of the engine and the pump. Thetappets are formed of square oblong blocks provided with side lips 2, which fit over and form guides for the and exhaust of 5 main exhaust of the cylinder.

blocks upon the rod, and they are formed with slots 1', through which screw-bolts'k pass to clamp the block-tappets upon the rod'aud allow them to be adjusted nearer to or far- 5 ther apart, so that the valve will be oscillated more orless, and thus admit steam for a longer or shorter time. the square-edges of pets in perfect alignment therewith, and the to acting ends of the tappets are rounded, as

seen in Fig. 7. Making the valve-shiftin g rod with a square flat seating 5 for the tappetblocks, and fitting the latter with their flat faces upon such fiat seating and with their r 5 side lips 2 2 over the sides of such flat seat- 1ug give the advantage of firmly and solidly securing the tappet-block by a bolt passing through it into the rod, whereby the blocks are not so liable to be knocked loose as is the case with the tappet-collars'secured by a screw, the point only of which gives the clamping force and is liable to be jarred loose and to slip upon the rod. The tappet-carrying end of the rod I is fitted in a guide-ring I,

fastened to the side of the valve-chest bonnet,

as seen in Fig. 5.

To permit of the slow operation of the pump when desired and prevent its stopping,which it would be liable to do from variations in a the pressure of the steam and from the action of water from condensed steam, as is the case with what are called cushion-valves, nowiu use in steam-pumps,I provide a throttle-valve of novel construction and in its ar- 3 5 rangement and combination with the engineoperating valve, as I shall now describe.

At a point between the exhaust-passage of the piston,which operates the slide-valve and the exhaust of the power-cylinder, I arrange 40 this throttle-valve L, which consists of a cirwheel Z A small hole m is drilled in the valve-head first centrally, so as to open at the bottom of said valve, and then obliquely, so as to open at the side of the valve above its beveled face, as seen in Figs. 2 and 6, so that when the valve is screwed down upon its seat there will be a steanrpassage through said hole, leading from the oscillating valve to each end of the piston-slide-operating valve, and thereby prevent the stopping of the pump, as enough steam will pass through this valve-hole to cause the constant operation of the engine so long as steam is admitted to the oscillating valve. valve also causes the slide-valve to travel slowly admitting the steam more gradually into the cylinder and causingthe pump to run steadily, and by means of its adjustment The t-appet-lips. 2 fit over, the rod and keep the tap and valve-connections. allows of the adjustment of the piston-rods This throttlethe pressure of the steam can be regulated as may be desired. This construction and arrangement of throttle-valve will permit the escape of water from the condensed steam when the valve is closed upon its seat, and thus avoid the stopping of the engine from the accumulation of water in the steam-passages from the oscillating valve.

The oscillating valve receives 1ts motion, as stated, by means of the tappet-arm and tappets on the rod which connects with the piston-rod cross-head. This cross-head 1s adapted to connect the separate piston-rods N N for the steam and for the water-cylinder-pistons for the purpose of permltting the removal of either or both the pistons from their respective cylinders by merely taking off the outer cylinder-bonnets and a' cap from the cross-heads. "This is of specialamportance in mining-pumps, in which the piston and piston-rod of the water-cylinder are cutout and destroyed in a comparatively short time by the acids in the water. The construction which I prefer to use for thls purpose is shown in Figs. 1 and 8, and consists in having a separate piston-rod for each piston, screw-threadin g the meeting ends of the piston-rods and providing the hub end of the cross-head with a screw-threaded bore into which the screw ends of the piston-rods are secured. The bore of the cross-head is divided by a threaded cap 4, which is removably secured by screw-bolts, so that by taking off the cap and removing the outer bonnet of the pump-cylinder the piston and its rod can be drawn out and a new one can be replaced without disturbing the steam-cylinder piston This construction within the cross-head to exactly suit the stroke of the piston within the cylinder, or both of them, and when so adjusted the screw-cap can be clamped hard upon the threaded ends of the piston- *ods to hold them secure. My improvements also give the advantage of great convenience for renewing the lining of the water-cylinder when required, and of removing and renewing the valves of the water-chest.

Referring to the oscillating valve, I prefer to use the circular fiat construction shown in my patent of June 7, 1881, for steam-pump, and to arrange it within the side of an auxiliary-valve chest and to operate the slidevalve by a double-ended piston -valve arranged within a main-valve chest and communicating with the oscillating flat-faced valve, which is operated from the steam piston-rod and has a balanced action, The auxiliary-valve chest is bored out and faced ott on the inner side for the oscillating valveseat, and said valve is ground olf on both sides to fitsaid seat and the inner side of the valve-chest bonnet, so thatthere shall be no endplay to said valve, and which works free under any pressure.

I claim as my improvements- I. In a steampumping-engine, the combination, with an oscillating valve F and a piston-operated slide-valve E, of a tln'ottle-valve ll, located between the exhaust-passage of the piston-operated slide-valve and the exhaustpassage of the power-piston, and having an opening 211 through its face, and a screw-op eratin stem, whereby when the said valve is closed the said exhaust-passages will be in communication through the opening in the said valve for operating the pump when the throttle-valve is closed.

2. I11 a steam pumping-engine, the valveshifting rod I, formed with a square flat facing 5, the tappet-blocks 71, h, of oblong square form, each provided with the side lips 22 and fitting the face and sides of the square fiatfacing 5, the slot 1' in said block, and the bolt 71:, passing through said slot into said square facing, in combination with the oscillating valve F, having a tappet-arm II, whereby the blocks are solidly clamped and firmly secured upon a square flat seating, as described.

3. In a steam pumping-engine, the combination of the steam and Water cylinders, their separate piston-connecting rods N N, having screw-threaded ends, the oscillating valve F, and its shifting-rod I, with a cross-head K, having a screw-threaded bore and a removable serew-threaded cap 4, matching the screwthreads of said here, the screw-threaded ends of said piston-rods m at-ehing the screwthreaded bore of the cross-head and its cap, whereby the pistons may be set relatively within their respective cylinders and separately removed therefrom.

4. In a steam pumping-engine, the combi' nation of the pump and the engine, the rods N N, connecting their pistons, the steamchest C, having the oscillating valve F, the piston-operated slide-valve D, and a throttlevalve L, located between the exhaust-passage of the said piston-operated slide-valve and the exhaust-passage of the powercylinder and having an opening m in its face, and a screw-operating stem, and means for connecting the said oscillating valve with the engine and pump pistons, whereby when the said throttle-valve is closed the said exhaust-passages will be maintained in communication for containing the slow operation of the piston-operating slide-valve and the pump.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

DAVID EVANS.

\Vitn esses:

C. D. ScHELL, B. E. WITHERs. 

